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Biomedical subjects

E Caballero

Publications and source records attributed to E Caballero.

At least 37 records · Page 2Linked to original sources

Leishmanicidal activity of combretastatin analogues and heteroanalogues.

We have investigated the in vitro leishmanicidal activity of representative members from series II-V of combretastatin analogues and heteroanalogues. Most of them exhibited different degrees of activity against various strains of Leishmania spp. The diaryl(heteroaryl)ethane system or the more complex fused heterocyclic stilbenoids, constitute useful skeletal bases to support some kind of antiparasitic activity. Particularly, the incorporation of 2-furyl substituents led to potent antileishmanial compounds, which have been selected for in vivo testing on murine models.

Animals↗

Synthesis and inotropic activity of hydroindene derivatives.

A synthetic approach to hydroindenic inotropic agents has been developed, starting from enantiopure Hajos-Parrish (1). Hajos-Wiechert (2), and related diketones. Their transformation into C-1 formyl derivatives and other subsequent synthetic targets is described. The results of the thermodynamic equilibration between both epimers of each formyl derivative are analysed. The inotropic activities of selected compounds on right and left atrial preparations are also evaluated and discussed.

Animals↗

Human immunodeficiency virus type 2 infection in Spain. The HIV-2 Spanish Study Group.

The first cases of human immunodeficiency virus type 2 (HIV-2) infection in Spain were identified in 1988, in 3 African immigrants living in Barcelona. Since then, up to December 1998, 92 individuals with HIV-2 infection have been reported in Spain. Most are adult men, infected through heterosexual contacts, originating from West African countries, and currently living in the largest urban Spanish cities. Fifteen individuals have developed AIDS, meanwhile the rest remain asymptomatic. For 22 subjects, HIV-2 subtyping was performed on proviral DNA, 16 being infected with subtype A (8 Spanish born and 8 African immigrants) and the remaining with subtype B (two Spanish born and 4 originating from Equatorial Guinea). Coinfection with HIV-1 was demonstrated in 9 individuals. In conclusion, HIV-2 is currently circulating in Spain with a low prevalence and without evidence for increase over time.

Adult↗

Hydroindenic-guanylhydrazones. Synthesis and evaluation as inotropic agents.

The synthesis and inotropic activity of two families of hydroindenic compounds are described. Among them, a bis-guanylhydrazone derivative has demonstrated to produce an interesting positive inotropic effect on guinea pig atria, displaying at higher dosis a similar effect to that elicited by digoxin.

Animals↗

Influence of several adjuvants on the immune response against a recombinant meningococcal high molecular weight antigen.

Studying outer membrane proteins as vaccine candidates, our group has previously isolated, cloned, and expressed in Escherichia coli the gene encoding for a high molecular weight protein (P64k), common to many meningococcal strains. To continue the characterisation of this meningococcal antigen, we have evaluated its immunogenicity in mice alone or combined with several commercially-available adjuvants. We used as an adjuvant aluminium hydroxide (Alhydrogel and Rehydragel), aluminium phosphate, Algammulin, crude saponin, the saponin Quil A, dimethyl-dioctadecyl ammonium bromide (DDA), Freund's adjuvant, and Montanide 888. The antibody titres against the recombinant protein and whole meningococci elicited with these adjuvants were compared. We found that Quil A produced the highest titres against the recombinant P64k. Algammulin and the quaternary ammonium compound DDA induced the highest levels of antibodies against meningococci. We analysed the recognition of a set of linear peptides by antisera prepared against the protein combined with some of the adjuvants. The responses depended on the adjuvant used and the results have been confirmed by epitope mapping using overlapping peptides synthesised on pins.

Adjuvants, Immunologic↗

Expression in Escherichia coli of the lpdA gene, protein sequence analysis and immunological characterization of the P64k protein from Neisseria meningitidis.

By making use of recombinant DNA technology it is possible to characterize meningococcal outer membrane proteins (OMPs) capable of stimulating a host immune response. The lpdA gene, which codes for an OMP (P64k) from Neisseria meningitidis, was cloned in Escherichia coli. The recombinant protein was recognized by sera from patients convalescing from meningococcal disease. The monoclonal antibodies obtained against the recombinant protein recognized the natural protein on a Western blot, and monoclonal antibody 114 was assayed in ELISA with a panel of 85 N. meningitidis strains. The protein was recognized in 81 strains (95.3%); the strains that were not recognized were neither epidemic nor isolated from systemic disease. The complete amino acid sequence of P64k was obtained by automatic sequencing and MS.

Amino Acid Sequence↗

[Study of gastric emptying by dual isotopes. Corrections due to contamination].

The evaluation of gastric emptying by the double isotope technique involves some methodologic conditioning. Among them contamination correction or interference in the energy windows of the activity of the two isotopes used in the marking of the solids and fluids of the test food are important. The results of an experiment in which a phantom was used to evaluate the contamination between indio 111 (DTPA-Ca111In) and technecium 99m (colloid99mTc). Three test studies were posteriorly performed in healthy volunteers and 27 studies in a control group (13 males, mean age of 33 years, mean body mass index 39.02 kg/m). In these studies the contamination was corrected with the acquisition, following an initial swallow of juice marked with 111In, of activity in the windows of both isotopes. The contamination of 111In (isotope of greatest radiation energy) in the window of 99mTc was 24% in the phantom and 20%, 23% and 26% in the three initial study tests. The mean contamination in the control group was of 22% with limits of 19% to 29% and a standard deviation of 3%. Despite the comparable results, the usefulness of the individualized contamination calculation in the studies of gastric emptying with dual isotope to minimize the methodologic errors of this technique is discussed.

Adult↗

Antihypertensive effect of some oxazolo[3,2-a]pyridines, thiazolo[3,2-a]pyridines and pyrido[2,1-b]oxazines in conscious spontaneously hypertensive rats.

The antihypertensive activity of eighteen 'oxazolo[3,2-a]pyridine, thiazolo[3,2-a]pyridine and pyrido[2,1-b]oxazine derivatives has been evaluated in conscious spontaneously hypertensive rats (SHRs), and compared with that of nifedipine, used as reference. At a dose of 50 mg kg-1 (i.p.) eleven compounds resulted in a significant reduction in mean arterial blood pressure; four of the eleven were particularly effective, resulting in significant hypotension more than 6 h after administration and an effect that was still apparent after 24 h. The hypotension induced by nifedipine gradually decreased, disappearing 6-8 h after administration. The long-lasting activity shown by these compounds is, in general, not accompanied by reflex tachycardia. Intraperitoneal administration of two oxazolo[3,2-a]pyridine derivatives and two pyrido[2,1-b]oxazine derivatives resulted in potent and long-lasting antihypertensive action in SHRs. Further studies on the mechanism of action of these derivatives might help the determination of better structure-activity correlations and the design, synthesis and evaluation of better antihypertensive agents.

Animals↗

Epidemiology of human T-lymphotropic virus type II (HTLV-II) infection in Spain. HTLV Spanish Study Group.

The human T-lymphotropic virus type II (HTLV-II) has recently been associated with the genesis of some subacute neurological syndromes and, rarely, with atypical T-lymphoid malignancies. The virus is endemic in some Amerindian and African tribes, and among intravenous drug users (IDUs) in North America and Europe. Given that HTLV-II is transmitted by the same routes as other human retroviruses, the screening of antibodies to HTLV-II in blood donors has became a matter of controversy in some countries. Herein, we describe the clinical, epidemiological and virological features of 113 individuals with HTLV-II infection identified in Spain up to September 1995. Most of them (94/113; 83%) were male, and all but seven were natives. Four were African immigrants living in Madrid and 3 had been born in other European countries. All but six subjects were IDUs, and sexual transmission of HTLV-II and transfusion were involved in five and one individual, respectively. Eighty-four percent of the IDUs infected with HTLV-II were co-infected by HIV-I (93/107). Clinical manifestations potentially linked to HTLV-II were absent, although an IDU male co-infected by HIV-1 and HTLV-II developed a severe non-inflammatory proximal myopathy. In conclusion, HTLV-II infection is present in Spain, mainly among IDUs, with a growing incidence and a current overall prevalence of 2.0 percent.

Adult↗

Epidemiology of HIV-2 infection in Spain. The HIV-2 Spanish Study Group.

Human immunodeficiency virus type 2 (HIV-2) infection is endemic in West Africa, where it is responsible for many cases of AIDS. HIV-2-infected subjects have been described in other countries, mainly African immigrants, although infection in native individuals has been reported as well. The first cases of HIV-2 infection in Spain were identified in 1988. Through December 1995, 56 HIV-2 infected individuals have been diagnosed, primarily in large urban areas (23 cases in Madrid and 18 in Barcelona). All are African immigrants, except for 12 natives (21.4%), six of whom acquired the infection in endemic areas; the remaining six (2 women with numerous sexual partners and 4 homo/bisexual men) acquired the infection in Spain. Heterosexual transmission was probable in all but seven cases: five homo/bisexual males, a subject who likely acquired infection through parenteral exposure, and a child born to an HIV-2-infected mother. Nine patients (all Spanish born) have developed AIDS (16%), six of whom have died. In conclusion, HIV-2 infection is present in Spain at a low rate, and there is little evidence supporting an emerging ongoing transmission outside the population of African immigrants.

AIDS Serodiagnosis↗

National vitamin A survey in Panama.

The prevalence of vitamin A deficiency in a nationally representative sample of children 12-59 months old in Panama was assessed using serum retinol levels and dietary indicators. The median serum retinol level found was 1.27 +/- 0.42 mumol/L (38 micrograms/dL); 6.0% of the study sample providing adequate blood specimens had levels below 0.7 mumol/L (20 micrograms/dL), indicating deficient vitamin A intake. The Panama City Metropolitan Area and the country's western region had the highest prevalences of low serum retinol levels (below 0.7 mumol/L in 9% and 6% of the study children, respectively), as compared to overall prevalences of 5% in the two other regions studied. Low serum retinol levels were significantly more prevalent among Indians in the study group (primarily Guaymí Indians) than among non-Indians (13% versus 5%). Dietary information provided by the study children's mothers showed that high risk of inadequate dietary vitamin A intake closely paralleled low serum retinol levels; specifically, the highest prevalence of dietary inadequacy was found in the western region, especially among the Indians. The Panamanian Government is currently increasing distribution of high-dose vitamin A capsules to Indian preschoolers in Chiriquí and Bocas del Toro Provinces.

Child Nutrition Disorders↗

[Type 2 human immunodeficiency virus infection (HIV-2) in Spain: analysis of the first 50 cases. Spanish Group for the Study of HIV-2].

BACKGROUND: Infection by the human immunodeficiency virus type 2 (HIV-2) is endemic in West Africa where it is responsible for many AIDS cases. HIV-2 has been described in subjects in other countries, mainly in African immigrants, although it may also be found in natives. The first cases of HIV-2 infection were identified in Spain in 1988. METHODS: The clinical, epidemiologic and virologic characteristics of the subjects with HIV-2 infection identified in Spain up to November 1994 are described. RESULTS: Fifty people have been diagnosed with HIV-2 infection, being found mainly around the large urban centers (20 cases in Madrid and 16 in Barcelona). All the cases were African immigrants except for 10 Spaniards (20%), 6 of whom had acquired the infection in endemic areas while the other 4 (one prostitute from Barcelona and 3 bisexual males from Guipúzcoa) had acquired the infection in Spain. Heterosexual transmission was implicated in all the cases except in 6 subjects (4 bisexual males, one case of probable intravenous transmission and one vertically infected child). Eight (all Spanish) patients have developed AIDS and 5 have died to date. At least 10 other subjects have a CD4+ lymphocyte count lower than 0.2 x 10(9)/l, one being the only pediatric patient (6-year-old male). CONCLUSIONS: HIV-2 infection is present in Spain, although there is no evidence for a rapid dissemination of the virus outside the collective of African immigrants. The Spaniards with HIV-2 infection represent 20% of the cases having contracted the virus through sexual relations with natives from endemic areas.

Acquired Immunodeficiency Syndrome↗